Collapsible fish trap with acoustic masking properties

ABSTRACT

Various aspects of the disclosure generally relate a fish trap for use in waters among marine predators which use echolocation. In one aspect the fish trap has acoustic masking properties. In one aspect the fish trap may be a lightweight, collapsible column for use by small commercial vessels and recreational fishing. In one aspect the fish trap may have an overlapping net, forming a double seam for added strength. In one aspect the fish trap may have reinforcing wire along bridle attachment points to hold heavier loads of fish.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation that claims priority under 35 U.S.C.§ 120 to U.S. patent application Ser. No. 17/408,395, filed Aug. 21,2021, which claims priority to U.S. Provisional Patent Application No.63/068,901, filed Aug. 21, 2020, each hereby incorporated by referencein their entirety.

BACKGROUND Field of the Disclosure

Aspects of the disclosure relate to fishing, and to a fish trap usablein waters subject to predation.

Description of Related Art

Commercial fishing for halibut and sablefish in Alaska is largely fishedby smaller boats under 100 feet in length. Historically in southeastAlaska, West Yakutat and the Central Gulf of Alaska, sablefish werefished with both longline hook gear (consisting of thousands of hooksattached to line that lay at the bottom of the ocean—herein referred toas longline) or longline “pot” gear, consisting of large rigid framefish trap “pots” weighing between 40-200 pounds each (herein referred toas pot or pots). The “pot” terminology comes from the fact thattraditional sablefish pots are derived from Alaskan king crab pots. Incommercial fishing, “pots” typically refer to large, rigid-framed fishtraps. Pots have the advantage of being robust and capable of holdinglarge quantities of fish. They also rely on their robust construction toresist whale depredation on fishing gear. Pots can be used in watersheavy with predators such as whales, as the pots create a rigid metalcage around the catch and are fairly resistant to predation. In order tomake it easier for fishing boats to raise pots from deep in the watercolumn without capsizing their vessel or straining their hydraulicsystems, pots are made with low surface density, which reduces dragproduced when rapidly hauling the pot through the water. One way toachieve low surface density is using the largest possible hole size inthe net that prevents fish from escaping, along with thin netting (smalldiameter netting material).

Fishing sablefish with pots has been practiced in the Alaskan fisherysince the early 70s but due to gear conflicts with longline boats it wasphased out in much of Alaska during the late 1980s. During this periodthe Canadian commercial fishery fished predominantly with fish pots,largely of the nesting conical design originally modified from tanner orsnow crab traps. In Washington, Oregon, and California, fishingsablefish with pots has remained legal and hundreds of small boatsparticipate in that fishery off the West Coast with both pot andlongline hook gear. Size and weight constraints dictate that smallervessels fish with longline hook gear instead of pots.

One current design for a sablefish pot is a large, rigid trapezoidalframe (with a top square of slightly smaller dimensions connected to thelarger bottom square by rigid steel) covered in netting. Another designis a rigid conical frame consisting of two metal hoops (one about ⅔ thediameter of the other) connected by welded metal supports. Both of thesetrap designs are typically made of mild carbon steel and weigh 40-200pounds depending on the size. In some regions of the US andinternationally there have been experiments with collapsible cod traps,notably large, rectangular folding designs that are suspended above thesea floor with floats.

Numerous pots attached to a retrieval line being pulled from the oceanhave a cumulative drag requiring large, heavy and powerful equipment toovercome. Sablefish pots typically use twisted nylon or braided PE meshwith a diameter under 3 mm and large mesh size, often 7-10 cm half mesh.This results in netting that is a balance between low surface density(i.e. a net with large holes and thin line) to reduce drag, while alsohaving a small enough mesh size and a strong enough line for catchingand retaining commercially valuable fish. Typical net surface densityfor these pots is 50-70 g/m². Here the netting is strong enough toprevent fish from escaping but the heavy steel frames are relied upon toresist whale attacks

Another type of fish trap, a spring trap, is used for recreationalfishing of minnows and shrimp (sometimes called crayfish traps). Thespring traps have a frame of plastic-coated iron wire or low tensilestrength steel, with twisted monofilament mesh netting. Scaling springtraps to a volume appropriate for commercial fishing does not make thesetraps suitable for commercial fishing for several reasons. Testing ofthe scaled-up recreational spring traps shows them to be easily damagedduring use, and susceptible to whale predation while fishing.

Small-vessel fishing fleets are unable to utilize pots, and fishing withlongline hooks presents several challenges. Depredation by orca or spermwhales can cause significant loss of their catch. Hooks areindiscriminate and catch large amounts of bycatch, including sharks,rays, skates and seabirds. Hooks require laborious hand baiting on smallboats which is time consuming for the crew. What is needed is acollapsible, lightweight fish trap usable by smaller fishing boats andsuitable for catching commercially valuable fish without beingsusceptible to predation.

SUMMARY

This disclosure recites a fish trap having a helical spring with athickness greater than or equal to 6 mm. The fish trap may be configuredto have an expanded state, the spring in the expanded state having theapproximate shape of a column with a diameter greater than 50 cm and alength greater than 100 cm. A net may be coupled to the spring forming aside wall for the approximately shaped column. A first end wall and asecond end wall may be at the two opposite ends of the helical spring,lengthwise, each of the first end wall and the second end wall having aweb, the helical spring having an interior defined by the bounds of thenet and the web at each of the first and second end walls. The net mayhave a surface density from 110 grams/meter squared to 350 grams/metersquared. A first hoop in the first end wall may be coupled to the web inthe first end wall and may create a first entrance, the first hoophaving a diameter less than the diameter of the column, the first hoopconfigured to allow fish to access the interior of the fish trap. Thenet may have a half mesh size less than 6 centimeters, be composed of aknotless material and be selected from the group consisting ofpolyethylene or nylon.

The fish trap may further include a second hoop in the second end wallcoupled to the web in the second end wall and creating a secondentrance. The second hoop may have a diameter less than the diameter ofthe column and the second hoop may be configured to allow fish to accessthe interior of the fish trap. The trap may have a plurality of cordscoupled to the first hoop and to the second hoop, the plurality of cordsextending in approximately a straight line when the spring is in theexpanded state. A mesh may be separately coupled to each of the firsthoop and the second hoop, each mesh and hoop combination configured toform a funnel to the interior of the fish trap when the spring is in theexpanded state, the plurality of cords coupled between the mesh at eachof the first and second hoops and configured to create the funnel ateach of the first end wall and second end wall. The net and the web havethe same acoustic signature. The door may be configured to allow removalof fish caught in the fish trap. A plurality of escape rings may bepositioned on the side wall, the plurality of escape rings each having adiameter less than the diameter of the first hoop. A partial hoop may becoupled to the spring and coupled to the web in the first end wall, thepartial hoop and web forming the first end wall and the door, thepartial hoop configured to securely attach to the spring in a closedposition. When the partial hoop is in the closed position, it may beconfigured to provide access through the first hoop by fish to theinterior, the door configured to swing into an open position and deformthe first end wall. The door may be configured to provide greater accessto the interior when in the open position than the access provided tothe interior by the first hoop. A support line may be coupled to eachend of the helical spring, lengthwise, extending from one end of thespring to the other end of the helical spring. A separate support wiremay be coupled to the helical spring at each end, the support wires ateach end extending along the helical spring for less than half thecircumference of the column, the support wires configured to providestrength and rigidity to the helical spring during retrieval of the fishtrap. The support line may be coupled to the helical spring on a sideopposite the support wires, the support line running in approximately astraight line and further coupled to the helical spring where thesupport line crosses the helical spring. The net may have an overallwidth greater than the circumference of the helical spring such that thenet overlaps itself along the length of the helical spring by at leastone square of netting, forming a double seam. The net may be coupled toitself along each end of the double seam overlap.

The fish trap may be configured to have a collapsed state. The fish trapwhen in the collapsed state having a cross-sectional area of less thanone quarter the cross-sectional area of the fish trap while in theexpanded state. The net may be coupled to the helical spring only at theends of the helical spring, lengthwise, the net and the helical springfree from one another between the first end wall and the second endwall.

A fish trap may include a helical spring with a thickness greater thanor equal to 6 mm and be configured to have an expanded state. The springin the expanded state may have the approximate shape of a column with adiameter greater than 50 cm and a length greater than 100 cm. A net maybe coupled to the spring forming a side wall for the approximatelyshaped column. A first end wall and a second end wall may be formed atthe two opposite ends of the helical spring, lengthwise, each of thefirst end wall and the second end wall having a web. The helical springmay have an interior defined by the bounds of the net and the web ateach of the first and second end walls. A first hoop in the first endwall may be coupled to the web in the first end wall and create a firstentrance. The first hoop may have a diameter less than the diameter ofthe column. The first hoop may be configured to allow fish to access theinterior of the fish trap. A first support wire may be coupled to thehelical spring at the first end wall, the first support wire may extendalong the helical spring for less than half the circumference of thecolumn. A second support wire may be coupled to the helical spring atthe second end wall. The second support wire may extend along thehelical spring for less than half the circumference of the column.

A fish trap may include a helical spring with a thickness greater thanor equal to 6 mm, configured to have an expanded state. The spring whenin the expanded state may have the approximate shape of a column with adiameter greater than 50 cm and a length greater than 100 cm. A net maybe coupled to the spring forming a side wall for the approximatelyshaped column, a first end wall and a second end wall at the twoopposite ends of the helical spring, lengthwise. Each of the first endwall and the second end wall may have a web. The helical spring may havean interior defined by the bounds of the net and the web at each of thefirst and second end walls. A first hoop in the first end wall may becoupled to the web in the first end wall and may create a firstentrance. The first hoop may have a diameter less than the diameter ofthe column. The first hoop may be configured to allow fish to access theinterior of the fish trap. A support line may be coupled to each end ofthe helical spring, lengthwise, extending from one end of the spring tothe other end of the helical spring. The support line may run inapproximately a straight line and further coupled to the helical springwhere the support line crosses the helical spring.

A fish trap may include a helical spring with a thickness greater thanor equal to 6 mm, configured to have an expanded state. When the springis in the expanded state it may have the approximate shape of a columnwith a diameter greater than 50 cm and a length greater than 100 cm. Anet may be coupled to the spring forming a side wall for theapproximately shaped column. The net may have an overall width greaterthan the circumference of the helical spring such that the net overlapsitself along the length of the helical spring by at least one square ofnetting. The overlap may form a double seam. The net may be coupled toitself along each end of the overlap. A first end wall and a second endwall may be at the two opposite ends of the helical spring, lengthwise,each of the first end wall and the second end wall having a web. Thehelical spring may have an interior defined by the bounds of the net andthe web at each of the first and second end walls. A first hoop in thefirst end wall may be coupled to the web in the first end wall and maycreate a first entrance. The first hoop may have a diameter less thanthe diameter of the column. The first hoop may be configured to allowfish to access the interior of the fish trap.

A fish trap may include a helical spring with a thickness greater thanor equal to 6 mm, configured to have an expanded state and a collapsedstate. The spring when in the expanded state may have the approximateshape of a column with a diameter greater than 50 cm and a lengthgreater than 100 cm. The fish trap when in the collapsed state having across-sectional area of less than one quarter the cross-sectional areaof the fish trap while in the expanded state. A net may be coupled tothe spring forming a side wall for the approximately shaped column, afirst end wall and a second end wall at the two opposite ends of thehelical spring, lengthwise. Each of the first end wall and the secondend wall may have a web. The helical spring may have an interior definedby the bounds of the net and the web at each of the first and second endwalls. A first hoop in the first end wall may be coupled to the web inthe first end wall and may create a first entrance. The first hoop mayhave a diameter less than the diameter of the column. The first hoop maybe configured to allow fish to access the interior of the fish trap.

The foregoing has outlined rather broadly the gestures and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of this disclosure. Such equivalent constructions do not departfrom the scope of the appended claims. Characteristics of the conceptsdisclosed herein, both their organization and method of operation,together with associated advantages will be better understood from thefollowing description when considered in connection with theaccompanying figures. Each of the figures is provided for the purposesof illustration and description, and not as a definition of the limitsof the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the disclosure can be understoodin detail, a more particular description, briefly summarized above, maybe had by reference to aspects, some of which are illustrated in theappended drawings. It is to be noted, however, that the appendeddrawings illustrate only certain typical aspects of this disclosure andare therefore not to be considered limiting of its scope, for thedescription may admit to other equally effective aspects. The samereference numbers in different drawings may identify the same or similarelements.

FIG. 1 is an environmental perspective view of fish traps being used incommercial fishing.

FIG. 2 is a perspective view of one fish trap from FIG. 1 in an expandedstate.

FIG. 3 is a perspective view of one fish trap from FIG. 1 in a collapsedstate.

FIG. 4 is a plan view of an end wall of a fish trap.

FIG. 5 is a side plan view of a fish trap.

FIG. 6 is a cut-away side plan view of a fish trap, removing two layersof netting in order to provide detail on the inner netting.

FIG. 7 is a partial perspective view of a fish trap with an open door.

FIG. 8 is a partial perspective view of a net illustrating a doubleseam.

FIG. 9 is a partial perspective view of a net illustrating a singleseam.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully herein withreference to the accompanying drawings. This disclosure may, however, beembodied in many different forms and should not be construed as limitedto any specific structure or function presented throughout thisdisclosure. Rather, these aspects are provided so that this disclosurewill be thorough and complete, and will fully convey the scope of thedisclosure to those skilled in the art. Based at least in part on theteachings herein, one skilled in the art should appreciate that thescope of the disclosure is intended to cover any aspect of thedisclosure disclosed herein, whether implemented independently of orcombined with any other aspect of the disclosure. For example, anapparatus may be implemented, or a method may be practiced using anynumber of the aspects set forth herein. In addition, the scope of thedisclosure is intended to cover such an apparatus or method which ispracticed using other structure, functionality, or structure andfunctionality in addition to or other than the various aspects of thedisclosure set forth herein. Any aspect of the disclosure may beembodied by one or more elements of a claim.

FIG. 1 is an environmental perspective view of fish traps being used incommercial fishing, designated generally with reference numeral 100 inthe figures. Fish trap 100 a is illustrated in an expanded state andfish trap 100 b is in a partially collapsed state (collectively referredto as fish trap or fish traps 100). While reference is made throughoutthis disclosure to commercial fishing and aspects of commercial fishing,this disclosure applies equally to recreational fishing and subsistencehunting. Fish trap 100 may be used to trap a variety of fish withcommercial or food value, for example Pacific cod, Atlantic cod,Greenland turbot, Pacific halibut, Patagonian toothfish (Chileanseabass, New Zealand ling, ling cod and sablefish.

In one aspect, fish traps 100 may be stored in a collapsed state (notshown in FIG. 1 , see FIG. 3 ) on board fishing boat 102. Alternatively,fish traps 100 may be stored in any position between collapsed andexpanded, as preferred by the fishermen. For deployment, anchor 104attached to retrieval line 106 is released from boat 102. Attachmentpoints 108 to retrieval line 106 may be any means of attachment, forexample a butterfly knot (lineman's loop). Connecting to attachmentpoint 108 is bridle 110, which may connect to attachment point 108 with,for example, a carabiner (not shown). Bridle 110 attaches to both endsof fish trap 100 by an appropriate means, for example a suitable knot orcarabiner. As retrieval line 106 spools out from boat 102, traps 100enter the water and come to rest on the ocean seabed (SB) in expandedstate fish traps 100 a. Depending on the type of fishing, bait may ormay not be used in traps 100.

The presence of large quantities of fish attracts both human and marinehunters. Schools of fish may be hunted by a variety of whales and otherpredators. One such predator, the orca whale or killer whale, locatesand hunts using echolocation, which may also be used by other marineanimals for hunting. By producing a series of high-frequency sound wavesand listening for the echo, orcas may determine the size, shape,structure, composition, speed, and direction of a fish or schools offish. In the case of traditional longline fishing the whales are able topick off individual fish from the longline, sometimes consuming nearlyan entire catch. An orca may grow up to eight meters in length and weighup to six tons, making them formidable creatures. Sperm whales can growto 16 meters and 40 tons and are also a primary predator on thesablefish fishery off the Alaskan coast. Evidence shows that both spermwhales and orcas try to access traditional rigid pot traps (pots) filledwith fish, but are generally unsuccessful because the pots have a strongsteel frame that prevents the whales from destroying the pots andaccessing the catch. In contrast, fish traps 100 may have a lightweightbendable frame that allows for partially collapsed and collapsed states,making them manageable for small boats and their crews. Rather than astrong steel frame to protect the catch, fish traps 100 acousticallymask their contents (fish). Fish traps 100 may be filled with fish, forexample cod or sablefish, while whale pods swim within meters of boat102 and the whales make no attempt to interfere with fish traps 100 orobtain the fish. Further aspects of fish traps 100 are discussed below.

When retrieving fish traps 100, boat 102 may pull from the waterretrieval line 106. As line 106 comes taut at attachment point 108,bridle 110 pulls on opposite ends of fish traps 100. The effectivesurface area of fish traps 100 is governed in part by materialcomposition and in part by cross-sectional area, and this bears arelationship to the amount of drag presented by each fish trap 100through the water. As bridle 110 pulls on the ends of fish trap 100, theresult is partially collapsed fish trap 100 b. Partially collapsed fishtrap 100 b has a lower drag than it would as expanded fish trap 100 a,allowing for more fish traps 100 to be handled by a given strength ofretrieval line 106, a winch (not shown) on boat 102, and increasing thenumber of fish traps manageable by a given size of boat. Partiallycollapsed fish trap 100 b may be empty, filled with fish, or anywhere inbetween. Once partially collapsed fish trap 100 b reaches boat 102, thecrew may disconnect fish trap 100 from retrieval line 106 at attachmentpoint 108 and remove any fish. In recreational fishing, a bridle may notbe used and a fisherman's line may be attached to an end of fish trap100. In this aspect, fish trap 100 may not partially collapse.Recreational fishing may involve one trap at a time, so the cumulativedrag of multiple traps is not as much of an issue.

FIG. 2 is a perspective view of fish trap 100 from FIG. 1 . Helicalspring 200 is a frame around which net 202 is wrapped. Spring 200 may bemade of galvanized wire with a carbon content from 0.6% to 0.85% andhaving a thickness greater than or equal to 6 mm, or greater than orequal to 7 mm, or greater than or equal to 8 mm, for example. Spring 200may be coated with zinc aluminum alloy, which may help prevent oxidationfrom seawater. The tensile strength of spring 200 may be between 900 and1300 MPa, balancing rigidity/durability with spring collapsibility.Spring 200 may also be made from other materials, and have otherthicknesses, to the extent it retains a bendable and collapsiblequality. Spring 200 may hold fish trap 100 in an expanded state absentconstraints or outside force (e.g. drag in water), in an approximatelycolumn-like shape. In one aspect, the diameter of spring 200 (andcorrespondingly fish trap 100) may be greater than 50 cm with a lengthgreater than 100 cm. In one aspect, the length may be 150-155 cm. In oneaspect, the diameter may be 75-85 cm. In one aspect, the diameter may beapproximately 81 cm.

Net 202 forms sidewall 204 of the column and may be wrapped or securedat the two ends of spring 200. End wall 206 a and end wall 206 b(collectively referred to as end walls 206) are at opposite ends ofspring 200 and lead to interior 208 of fish trap 100. In one aspect, net202 is secured, wrapped, or otherwise attached at each end of spring 200(at end walls 206), and left free of spring 200 in between. Net 202 maybe outside of spring 200 and thus held to the column-like shape byspring 200. One benefit of an absence of attachment points between endwalls 206 with respect to net 202 and spring 200 is that during trapdeployment, retrieval line 106 (see FIG. 1 ) can undesirably wrap aroundfish trap 100, entangling it. Net 202 that is free to slide along spring200 does so without damage to fish trap 100. When fish trap 100 isretrieved the tangle can be resolved without damage. In one aspect, net202 may be intermittently attached to spring 200 in between end walls206, for example by clips, wires, ties, or spring 200 may be woven intonet 202. In one aspect, net 202 may be fully attached to spring 200 byclips, wires, ties or spring 200 may be woven into net 202. One benefitof attaching net 202 to spring 200 is reducing the surface over whichcaught fish will be supported by net 202.

Net 202 may be knotted or knotless, and may be made from polyethylene,ultra-high molecular weight polyethylene (UHMWPE), or nylon, forexample. Net 202 has a surface density from 110 grams/meter² (g/m²) to385 g/m², or from 110 g/m² to 350 g/m². Surface density may be measuredby weighing a square meter of net, for example. Net 202 has a highersurface density than both recreational (10-50 g/m²) and commercial(50-70 g/m²) fishing nets. The increase in surface density increases netstrength, which is unnecessary for containing fish, for example cod orsablefish, because commercial fishing nets are already strong enough tohold the fish for which they are intended. Greater surface densityincreases drag during retrieval. Although stronger, there is noexpectation that the increased net strength (by increased surfacedensity) could resist whale attack and that problem has been addressedby the commercial fishing industry with rigid steel-framed pots. Sonarand echolocation used by toothed whales, for example orcas and spermwhales, relies on density differences between seawater and the objectthey are trying to sense. These density differences impact the speed ofsound and cause part of the acoustic signal to reflect off of aparticular object. In many fish with gas-filled swim bladders (such aspacific cod or rockfish) this density difference is extreme and thegas-filled swim bladders create a large acoustic signature. Other fishsuch as halibut, Greenland turbot, sablefish, ling cod or Patagoniantoothfish lack a swim bladder and therefore whales are able to get lessof an acoustic signature. In the northern Pacific Ocean the fish mostimpacted by whale depredation are sablefish, Greenland turbot andhalibut. These species lack swim bladders and therefore produce asmaller acoustic “echo” than species with swim bladders. Due to thedensity difference between the netting and seawater using netting withhigher surface density than is necessary for fish containment alone canhide the fish contained within from predatory toothed whales. Here, thehigher mass of net per square meter provides an acoustic shield, ormask, of fish that may be within fish trap 100. Observation of whalesduring retrieval of fish traps 100 has indicated that the whales have nointerest in fish traps 100. Increased surface density is achieved, inone example with the material and net formation (e.g. knotted vsknotless) being held constant, by either increasing the thickness of thematerial, or decreasing the size of the holes (mesh), or a combinationof the two.

Net size may be measured by half or full mesh measurements,knot-to-knot. A half mesh knot-to-knot (HMKK) measurement would be fromone knot (or intersection in the case of knotless netting), to the nextnearest knot (or intersection). Typical commercial nets used forsablefish and cod may have 6-10 cm HMKK. In one aspect, net 202 has HMKKof 5 cm or less. Decreasing HMKK (thus decreasing the size of the“holes” in net 202) increases surface density, as would increasing thethickness of net 202. Knotless nets may also have increased surfacedensity as compared to traditional knotted material. In one aspect,braided PE material may be used for net 202 with a sufficiently smallHMKK and sufficiently thick lines. Given that commercial fishing netsfor cod and sablefish are sufficiently strong having a surface densityof 50-70 g/m², further increasing their surface density runs counter tothe need for decreased drag while retrieving pots. The collapsiblenature of fish traps 100 allows a larger surface density of netting tobe used to acoustically mask the fish within from whale predatorswithout causing extreme drag while the fish traps 100 are retrieved. Inone aspect, spring 200 contributes to the acoustical masking of fishwithin fish traps 100. Spring 200 may hide the acoustic signature offish, or it may contribute to confusion in identifying the contents offish traps 100.

In one aspect, surface density in g/m² is greater than ⅕^(th) theinternal volume of fish trap 100 as measured in liters.

End walls 206 a and end wall 206 b have, respectively, web 210 a and web210 b (collectively referred to as web 210). Web 210 may be made fromthe same material in the same way as net 202 and have the same surfacedensity. In one aspect web 210 has a different surface density than net202, or web 210 may have the same surface density but be madedifferently or from a different material. Each of web 210 a and 210 bconnects to hoop 212 a and hoop 212 b (collectively referred to as hoops212). Hoops 212 provide an entrance to fish trap 100 into which fish mayswim and be caught inside interior 208. Hoops 212 may be any sizesmaller than the diameter of fish trap 100 itself. In one aspect, hoops212 may be 20-25 cm and be formed from a 3 mm 304 stainless steel ring.In one aspect, hoops 212 may be adjustable and formed with a flexibleline, for example rope. In one aspect hoops 212 may be circular, or ovalin shape depending on the desired fish type. The size of hoops 212 isbased on the size of desired fish and determined by local customs andfishermen's experiences.

Each of end walls 206 a and 206 b includes doors 214 a and 214 b,respectively (collectively referred to as doors 214). Door 214 b is notillustrated in FIG. 2 for the sake of clarity (another view is providedin FIG. 7 ). Doors 214 provide access to interior 208. Doors 214 may bemirror images of each other on opposite sides, or they may differ fromone another. Doors 214 may be partially circular or hoop-like in shapeand attached to spring 200 such that they swing away from end walls 206.Doors 214 may be the same material as spring 200. Doors 214 may be 7 mmspring steel, for example. Door 214 b, for example, may besemi-permanently secured with cotton, per local regulations or custom,to prevent ghost fishing. In the case that fish trap 100 is lost at sea,eventually the cotton degrades and door 214 b opens. Fish entering thelost trap can then escape, preventing the trap from continuing to catchfish.

Door 214 a may be a dump door, for example, secured to spring 200 whilefishing and releasable by fisherman to remove fish once fish trap 100 israised from the sea. Web 210 a is secured in part directly to spring200, and on the opposite side to door 214 a. When door 214 a is “closed”and secured to spring 200, end wall 206 a is formed by web 210 aattached to hoop 212 a, spring 200 and door 214 a. Door 214 a may besecured by a clip, wire, carabiner, rope, or any other mechanism. Fishtrap 100 is configured for fishing when door 214 a is closed. When door214 b is “open” and not secured to spring 200, end wall 206 a collapsesand interior 208 can be accessed, for example when fisherman unload thecatch. A similar configuration may apply to door 214 b.

Escape rings 216 in sidewall 204 allow fish that are small enough toescape from fish trap 100. Escape rings 216 may be approximately 9 cm,and may be adjustable. The number of escape rings 216 may be dictated bycustom, or local regulations, as well as their size and placement.Escape rings 216 will have a diameter less than that of hoops 212.

Support line 218 may be tied from end wall 206 a to end wall 206 b (fromone end of spring 200 to the other end). While fish trap 100 is in anexpanded state, support line 218 is relatively straight. Where supportline 218 crosses a part of spring 200, it may be tied to spring 200 atthat point. More than one support line 218 may be used, for example two,three, four, etc. In one aspect, support line 218 may be predominantlyoutside fish trap 100 (except for the points it ties into spring 200).In one aspect, support line 218 may be interwoven with net 202. In oneaspect, support line 218 may be inside fish trap 100, within interior208. Multiple support lines 218 may be spaced evenly from one another,or they may be spaced to provide greater support where a load of fish isanticipated to rest.

Not specifically illustrated in FIG. 2 , a 7 mm line may be wrappedaround the end “circles” of spring 200 to provide abrasion resistanceand improve durability.

FIG. 3 is a perspective view of fish trap 100 in a collapsed state. Fishtrap 100 may be collapsed to one quarter, one third, one fifth, or someother fractional amount of its expanded state. Clips (not shown) may beattached on the sides to keep fish trap 100 collapsed. The collapsedstate is useful for transport and storage. Collapsed state differs frompartially collapsed state fish trap 100 b in FIG. 1 as evidenced byFIGS. 1 and 3 .

FIG. 4 is a plan view of end wall 206 a of fish trap 100. Spring 200forms the frame with web 210 a leading to hoop 212 a, leading tointerior 208. Because FIG. 4 is a plan view, fish trap 100 can be viewedthrough to the opposite side (to end wall 206 b, not referenced in FIG.4 ) and the other entrance for fish. Support wire 400 is a reinforcingmember attached to the end of spring 200. Support wire 400 may be atboth ends of fish trap 100. Although FIG. 4 is a plan view illustratingone end (end wall 206 a), either or both ends of spring 200 may havesupport wire 400. In one aspect, support wire 400 is 7 mm galvanizedsteel. Not illustrated in FIG. 4 , support line 218 may be positionedopposite support wire 400, running roughly perpendicular in direction(see FIG. 2 for lay of support lines 218). In one aspect, two supportlines 218 may be positioned across from support wire 400, for example ifsupport wire 400 is at a 12 o'clock position as illustrated in FIG. 4 ,then one support lines 218 may be positioned at 8 o'clock and another at4 o'clock, or 5 o'clock and 7 o'clock, for example. In one aspect, threesupport lines 218 may be evenly spaced from one another, with onesupport line 218 at 6 o'clock, one support line 218 at 10 o'clock, andone support line 218 at 2 o'clock. Number, location and spacing ofsupport line(s) 218 may be dictated by need.

FIG. 5 is a side plan view of fish trap 100. Helical spring 200 forms aframe around which net 202 is wrapped, creating a column-like shape. Net202 forms sidewall 204 of the column. End walls 206 a and 206 b may befunnels at each end of the column, formed by web 210 a and 210 b,respectively. Web 210 a is attached in part to spring 200 and in part todoor 214 a. Door 214 a is unsecured and slightly open in FIG. 5 . Web210 a may form a funnel leading to hoop 212 a. Web 210 b is attached inpart to spring 200 and in part to door 214 b. Door 214 b is unsecuredand slightly open in FIG. 5 . Web 210 b may form a funnel leading tohoop 212 b.

Attached between hoops 212 is cord 500. Cord 500 holds hoops 212 withina certain distance from each other such that web 210 is pulled into thefunnel shape helping to guide fish towards interior 208 of fish trap100. Attached to hoop 212 a is mesh 502 a. Attached to hoop 212 b ismesh 502 b. Mesh 502 a and 502 b (collectively referred to as mesh 502)form the end of the funnel from end walls 206 to interior 208. Mesh 502may be finer or have a lower surface density than net 202. Fish areguided by the funnel into fish trap 100 and caught. Escape rings 216allow some fish to escape, for example immature or unwanted catch.Support lines 218 may provide strength to fish trap 100.

FIG. 6 is a cut-away side plan view of fish trap 100, removing from viewtwo layers of net 202 and spring 200 in order to illustrate more clearlyinterior 208. Helical spring 200 forms a frame around which net 202 iswrapped, creating a column-like shape. Net 202 forms sidewall 204 of thecolumn. Web 210 a is attached in part to spring 200 and in part to door214 a. Door 214 a is closed in FIG. 6 . Web 210 a may form a funnelleading to hoop 212 a. Web 210 b is attached in part to spring 200 andin part to door 214 b. Door 214 b is closed in FIG. 6 . Web 210 b mayform a funnel leading to hoop 212 b.

Attached between hoops 212 is cord 500. Cord 500 holds hoops 212 withina certain distance from each other such that web 210 is pulled into thefunnel shape helping to guide fish towards interior 208 of fish trap100. Attached to hoop 212 a is mesh 502 a. Attached to hoop 212 b ismesh 502 b. Mesh 502 a and 502 b form the end of the funnel to interior208. Fish are guided by the funnel into fish trap 100 and caught.

FIG. 7 is a partial perspective view of fish trap 100 with door 214 inan open position. Physical structure and aspects of fish trap 100 arenot illustrated in FIG. 7 in order to more clearly focus on door 214.Net 202 is not shown in FIG. 7 , however in some aspects net 202 and web210 may be a single, connected piece of netting. In one aspect, net 202and web 210 are separate, but both tied to spring 200 at the end,opposite from door 214. In one aspect, abrasion line 700 is wrappedaround an end of spring 200 for protection from abrasion.

When door 214 is unsecured it may open to allow access to interior 208.As door 214 opens, web 210 is no longer held in a funnel shape and thefunnel collapses toward the side of fish trap 100. Support wire 400 maybe opposite doors 214. Bridle 110 may be connected to fish trap 100 atsupport wire 400, so that as bridle 110 is lifted into the air aboveboat 102 (and lifts fish trap 100), doors 214 are at the bottom and onceopen ease the removal of catch.

FIG. 8 is a partial perspective view of net 202 illustrating a doubleseam. Net 202 may wrap around spring 200 with an overlap of one or moremesh holes where net 202 comes back together. FIG. 8 illustrates anoverlap of five mesh holes, but fewer or more mesh holes could beoverlapped. Net line 800 a secures net 202 to itself at one end of thedouble seam and net line 800 b (net line 800 a and net line 800 bcollectively referred to as net lines 800) ties net 202 to itself at theother end of the double seam. Also pictured is support line 218, towhich net lines 800 and the double seam run roughly parallel. Althoughnet lines 800 are illustrated, other means of securing mesh holes toeach other may be used, for example clips, wires, ties, staples, etc.

FIG. 9 is a partial perspective view of net 202 illustrating a singleseam. Net 202 may wrap around spring 200 without an overlap and a singleseam where net 202 comes back together. Net 202 may be secured withrings 900. Although rings 900 are illustrated, other means of securingnet 202 to itself may be used, for example clips, wires, ties, staples,a line, etc.

While commercial fishing is mentioned throughout this description, oneof skill in the art will recognize that fish traps 100 are equallyapplicable and useful for recreational fishing and hunting. Nothing inthis description should be taken as limiting in how fish traps 100 areused, other than that they provide a means of fishing among predatorswhich have echolocation, and saving on weight, size and cost of gear.

The aspects and features mentioned and described together with one ormore of the previously detailed examples and figures, may as well becombined with one or more of the other examples in order to replace alike feature of the other example or in order to additionally introducethe feature to the other example.

The description and drawings merely illustrate the principles of thedisclosure. Furthermore, all examples recited herein are principallyintended expressly to be only for pedagogical purposes to aid the readerin understanding the principles of the disclosure and the conceptscontributed by the inventor(s) to furthering the art. All statementsherein reciting principles, aspects, and examples of the disclosure, aswell as specific examples thereof, are intended to encompass equivalentsthereof.

A functional block denoted as “means for . . . ” performing a certainfunction may refer to a circuit that is configured to perform a certainfunction. Hence, a “means for something” may be implemented as a “meansconfigured to or suited for something”, such as a device or a circuitconfigured to or suited for the respective task.

It is to be understood that the disclosure of multiple acts, processes,operations, steps, or functions disclosed in the specification or claimsmay not be construed as to be within the specific order, unlessexplicitly or implicitly stated otherwise, for instance for technicalreasons. Therefore, the disclosure of multiple acts or functions willnot limit these to a particular order unless such acts or functions arenot interchangeable for technical reasons. Furthermore, in some examplesa single act, function, process, operation or step may include or may bebroken into multiple sub-acts, -functions, -processes, -operations or-steps, respectively. Such sub acts may be included and part of thedisclosure of this single act unless explicitly excluded.

Furthermore, the following claims are hereby incorporated into thedetailed description, where each claim may stand on its own as aseparate example. While each claim may stand on its own as a separateexample, it is to be noted that—although a dependent claim may refer inthe claims to a specific combination with one or more other claims—otherexamples may also include a combination of the dependent claim with thesubject matter of each other dependent or independent claim. Suchcombinations are explicitly proposed herein unless it is stated that aspecific combination is not intended. Furthermore, it is intended toinclude features of a claim to any other independent claim even if thisclaim is not directly made dependent on the independent claim.

The invention claimed is:
 1. A fish trap comprising: a spring with athickness greater than or equal to 6 mm, configured to have an expandedstate, the spring in the expanded state having a width greater than 50cm and a length greater than 100 cm; a net coupled to the spring forminga side wall, first end wall and a second end wall at the two oppositeends of the spring, lengthwise, each of the first end wall and thesecond end wall having a web, the spring having an interior defined bythe bounds of the net and the web at each of the first and second endwalls, the net having a surface density at least 110 grams/metersquared; and a first hoop in the first end wall coupled to the web inthe first end wall and creating a first entrance, the first hoop havinga width less than the width of the spring, the first hoop configured toallow fish to access the interior of the fish trap.
 2. The fish trap ofclaim 1, the net having a half mesh size less than 6 centimeters.
 3. Thefish trap of claim 1, the net comprising a knotless material.
 4. Thefish trap of claim 1, the net being a material selected from the groupconsisting of polyethylene or nylon.
 5. The fish trap of claim 1,further comprising: a second hoop in the second end wall coupled to theweb in the second end wall and creating a second entrance, the secondhoop having a width less than the width of the spring, the second hoopconfigured to allow fish to access the interior of the fish trap.
 6. Thefish trap of claim 5, further comprising: a plurality of cords coupledto the first hoop and to the second hoop, the plurality of cordsextending in approximately a straight line when the spring is in theexpanded state.
 7. The fish trap of claim 6, further comprising: a meshseparately coupled to each of the first hoop and the second hoop, eachmesh and hoop combination configured to form a funnel to the interior ofthe fish trap when the spring is in the expanded state, the plurality ofcords coupled between the mesh at each of the first and second hoops andconfigured to create the funnel at each of the first end wall and secondend wall.
 8. The fish trap the claim 5 wherein the net and the web havethe same acoustic signature.
 9. The fish trap of claim 1, furthercomprising: a door configured to allow removal of fish caught in thefish trap.
 10. The fish trap of claim 9, further comprising: a pluralityof escape rings positioned on the side wall, the plurality of escaperings each having a diameter less than the diameter of the first hoop.11. The fish trap of claim 10, the door further comprising: a partialhoop coupled to the spring and coupled to the web in the first end wall,the partial hoop and web forming the first end wall and the door, thepartial hoop configured to securely attach to the spring in a closedposition, and when in the closed position configured to provide accessthrough the first hoop by fish to the interior, the door configured toswing into an open position and deform the first end wall, the doorconfigured to provide greater access to the interior when in the openposition than the access provided to the interior by the first hoop. 12.The fish trap of claim 11, further comprising: a support line coupled toeach end of the spring, lengthwise, extending from one end of the springto the other end of the spring.
 13. The fish trap of claim 12, furthercomprising: a separate support wire coupled to the spring at each end,the support wires at each end extending along the spring for less thanhalf the circumference of the column, the support wires configured toprovide strength and rigidity to the spring during retrieval of the fishtrap.
 14. The fish trap of claim 11, wherein the support line is coupledto the spring on a side opposite the support wires, the support linerunning in approximately a straight line and further coupled to thespring where the support line crosses the spring.
 15. The fish trap ofclaim 11, wherein the net has an overall width greater than thecircumference of the spring such that the net overlaps itself along thelength of the spring by at least one square of netting, forming a doubleseam, the net coupled to itself along each end of the overlap.
 16. Thefish trap of claim 11, further configured to have a collapsed state, thefish trap in the collapsed state having a cross-sectional area of lessthan one quarter the cross-sectional area of the fish trap while in theexpanded state.
 17. The fish trap of claim 11, wherein the net iscoupled to the spring only at the ends of the spring, lengthwise, thenet and the spring free from one another between the first end wall andthe second end wall.
 18. The fish trap of claim 9, wherein the hoopshape is circular.
 19. The fish trap of claim 9, wherein the hoop shapeis oval.
 20. The fish trap of claim 9, wherein the hoop shape isadjustable.
 21. The fish trap of claim 9, the hoop further comprising aflexible line.
 22. The fish trap of claim 1, wherein the spring shape ishelical.
 23. The fish trap of claim 1, the spring in the expanded statehaving the approximate shape of a column.
 24. A fish trap comprising: ahelical spring with a thickness greater than or equal to 6 mm,configured to have an expanded state, the spring in the expanded statehaving the approximate shape of a column with a diameter greater than 50cm and a length greater than 100 cm; a net coupled to the spring forminga side wall for the approximately shaped column, a first end wall and asecond end wall at the two opposite ends of the helical spring,lengthwise, each of the first end wall and the second end wall having aweb, the helical spring having an interior defined by the bounds of thenet and the web at each of the first and second end walls, the nethaving a surface density at least 110 grams/meter squared; and a firsthoop in the first end wall coupled to the web in the first end wall andcreating a first entrance, the first hoop having a diameter less thanthe diameter of the column, the first hoop configured to allow fish toaccess the interior of the fish trap.
 25. A fish trap comprising: aspring with a thickness greater than or equal to 6 mm, configured tohave an expanded state, the spring in the expanded state having theapproximate shape of a column with a diameter greater than 50 cm and alength greater than 100 cm; a net coupled to the spring forming a sidewall for the approximately shaped column, a first end wall and a secondend wall at the two opposite ends of the spring, lengthwise, each of thefirst end wall and the second end wall having a web, the spring havingan interior defined by the bounds of the net and the web at each of thefirst and second end walls, the net having a surface density at least110 grams/meter squared; and a first hoop in the first end wall coupledto the web in the first end wall and creating a first entrance, thefirst hoop having a diameter less than the diameter of the column, thefirst hoop configured to allow fish to access the interior of the fishtrap.